diff --git a/services/core/java/com/android/server/StorageManagerService.java b/services/core/java/com/android/server/StorageManagerService.java
index 58143edc6f3d..3e61530c3af2 100644
--- a/services/core/java/com/android/server/StorageManagerService.java
+++ b/services/core/java/com/android/server/StorageManagerService.java
@@ -1716,6 +1716,23 @@ private void onVolumeStateChangedLocked(VolumeInfo vol, int oldState, int newSta
     }
 
     private void onVolumeStateChangedAsync(VolumeInfo vol, int oldState, int newState) {
+        if (newState == VolumeInfo.STATE_MOUNTED) {
+            // Private volumes can be unmounted and re-mounted even after a user has
+            // been unlocked; on devices that support encryption keys tied to the filesystem,
+            // this requires setting up the keys again.
+            try {
+                prepareUserStorageIfNeeded(vol);
+            } catch (Exception e) {
+                // Unusable partition, unmount.
+                try {
+                    mVold.unmount(vol.id);
+                } catch (Exception ee) {
+                    Slog.wtf(TAG, ee);
+                }
+                return;
+            }
+        }
+
         synchronized (mLock) {
             // Remember that we saw this volume so we're ready to accept user
             // metadata, or so we can annoy them when a private volume is ejected
@@ -1741,13 +1758,6 @@ private void onVolumeStateChangedAsync(VolumeInfo vol, int oldState, int newStat
             }
         }
 
-        if (newState == VolumeInfo.STATE_MOUNTED) {
-            // Private volumes can be unmounted and re-mounted even after a user has
-            // been unlocked; on devices that support encryption keys tied to the filesystem,
-            // this requires setting up the keys again.
-            prepareUserStorageIfNeeded(vol);
-        }
-
         // This is a blocking call to Storage Service which needs to process volume state changed
         // before notifying other listeners.
         // Intentionally called without the mLock to avoid deadlocking from the Storage Service.
@@ -3369,7 +3379,7 @@ private boolean isSystemUnlocked(int userId) {
         }
     }
 
-    private void prepareUserStorageIfNeeded(VolumeInfo vol) {
+    private void prepareUserStorageIfNeeded(VolumeInfo vol) throws Exception {
         if (vol.type != VolumeInfo.TYPE_PRIVATE) {
             return;
         }
@@ -3396,11 +3406,15 @@ private void prepareUserStorageIfNeeded(VolumeInfo vol) {
     public void prepareUserStorage(String volumeUuid, int userId, int serialNumber, int flags) {
         enforcePermission(android.Manifest.permission.STORAGE_INTERNAL);
 
-        prepareUserStorageInternal(volumeUuid, userId, serialNumber, flags);
+        try {
+            prepareUserStorageInternal(volumeUuid, userId, serialNumber, flags);
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
     }
 
     private void prepareUserStorageInternal(String volumeUuid, int userId, int serialNumber,
-            int flags) {
+            int flags) throws Exception {
         try {
             mVold.prepareUserStorage(volumeUuid, userId, serialNumber, flags);
             // After preparing user storage, we should check if we should mount data mirror again,
@@ -3427,7 +3441,7 @@ private void prepareUserStorageInternal(String volumeUuid, int userId, int seria
                         + "; device may be insecure!");
                 return;
             }
-            throw new RuntimeException(e);
+            throw e;
         }
     }